Conventional mechanical seal assemblies are employed in a wide variety of environments and settings, such as for example, in mechanical apparatuses, to provide a fluid-tight seal. The sealing assemblies are usually positioned about a rotating shaft or rod that is mounted in and protrudes from a stationary mechanical housing.
A conventional sealing assembly generally comprises a sealing element formed of a metallic spring or metallic springs in parallel for biasing the sealing face elements. The biasing element biases the sealing face elements into sealing engagement with the shaft to form a fluid-tight seal.
FIG. 1 illustrates an example of a mechanical seal in the prior art. As shown, the illustrative prior mechanical seal 1 requires one or more springs 2 for applying a loading force to a seal face, formed by mating a rotating seal face 4 and a stationary seal face 5, and multiple housing components 3a-d. The multiple housing components include a spring holder 3a, a rotating seal face retainer 3b, a rotating elastomer bellows 3c and a drive band 3d. The prior art seal 1 further includes an O-ring 6 for the stationary seal face 5.
However, such sealing assemblies suffer from a number of deficiencies and disadvantages. Disadvantages of prior seals, such as the one shown in FIG. 1, include non-uniform seal-face loading, exposure of the spring to process fluid and clogging of debris in the spring. For example, the spring is typically exposed to the internal or process fluid of the mechanical apparatus being sealed, which can potentially degrade the spring, potentially leading to the failure of spring. In addition, springs and other movable biasing elements tend to lose their resilient biasing characteristics over time, impairing the efficiency of the seal.
Other and more specific objects of this invention will in part be obvious and in part be evident from the drawings and description which follow.